Color television apparatus



Nov. 28, 1950 H. .1. MURRAY 2,531,823

COLOR TELEVISION APPARATUS Filed Nov. l5, 1946 3 Fig B7 Patented Nov. 28, 1950 UNITED STATES PATENT OFFICE COLOR TELEVISION APPARATUS Howard J. Murray, New York, N. Y.

Application November 13, 1946, Serial No. 709,472

11 Claims. l This invention relates in general to stationary color control apparatus and more specifically to color control apparatus for television receiving apparatus.

One of the objects of the present invention is l to provide stationary apparatus non-mechanical which can be employed with television apparatus to transmit actions of colored images from a near to a remote place so that the said colored actions will be usefully reproduced in a naturah color at the said remote place.

Still another object of the present invention is to provide electro-electron-optical stationary means arranged so that light derived from an electron bean will be selectively colored in ar according to the characteristics of a related electron beam and transmitted color signals related to the said characteristics.

A still further object of the present invention is to provide stationary color television apparatus which can be used with conventional black and White transmission and reception.

`In the following description names will be given to parts for convenience of expression, but these names are intended to be as generic in their application to similar parts as the art will permit.

The present invention is a further development of the inventions disclosed in my U. S. Patents Nos. 2,169,071 issued Aug. 8, 1939 and 2,225,922 issued Dec. 24, 1940 and my U. S. applications Serial Nos. 534,227 filed May 5, 1944- 665,685 led April 29, 1946, now abandoned and A667,524 liled May 6, 1946, now abandoned.

The invention allows numerous physical embodiments and different types are herein illustrated for the purpose of showing the wide application of the invention, but it is understood that the drawings are largely. diagrammatic merely being sufficient in detail to show embodiments of the invention.

In the drawings:

Figure 1 is a diagrammatic presentation of color control television apparatus wherein polarized light is derived from an electron beam.

Figure 2 is a diagrammatic presentation of component color` television apparatus constituting a modification of the means of Figure 1.

Figure 3 is a diagrammatic presentation of still another modication of the color control means of Figure 1.

Figure 4 is a plan view of an embodiment of a light polarizing means.

Figure 5 is a plan View of a polarized light analyzing means.

Figure 6 is a plan view of an embodiment of a disc-like polarized light wave-changing means having three light double refracting sections of different characteristics.

Figure '7 is a plan View of an embodiment of the light wave-changing means of Figure 6 including a disc-shaped pile of double refracting film disc with the discs in one circular holdingrim piece. 4

Figure 8 is a modification of the polarized light` analyzing means of Figure 5.

Figure 9 is a modication in more or less diagrammatic form of the means of Figure 3.

Figure 10 is a sectional View in elevation of the double refracting discs constituting the wavechanging means of Figure '7.

Referring now to the embodiment of my invention as shown by Figure 1 there is seen a conventional image reproducing electron beam tube and associated fluorescent screen generally identified by the numeral I0 and conventionally from the terminals {i6-B energized as to produce an electron beam ll. This beam ll impinges on the screen portion 32 so that visible energy hereinafter designated as light l2-I3 is derived therefrom to be substantially reflected from the surface of the reflector I4 through the correcting lens I4-A to the focal point 20.

A conventional plane polarizing means I6 (see Figure 4) is positioned in the path of the reflected focused light l5 after it passes through the correcting lens Ill-A. The said means IB can be formed from conventional polarizing lm such as Polaroid and curved so as to be symmetricalhT arranged about the focal point 20, altho the said film can also be flat when required. It is also contemplated that in some embodiments the correcting lens I4--A will not be employed.

A light plane polarization rotating medium 3l preferably a solid dielectric medium is positioned so as to include the said focal point 20 as centrally as possible and to be operatively associated with the electrodes Iii-A and i9-A connected to the supply leads I3 and I9 in turn connected to a source of plane polarization rotating energy related to the energy supplied to electron beam tube lil such an image frame synchronizing pulses upon which is superimposed color field synchronizing pulses. It should be noted at this time that the light l5 may be passed through a conventional lter (not shown) so as to become monochromatic before passing the plane polarization means i5 if such light is desired. The medium 3l may be Wrapped With a magnetic flux producing Winding in place Aof the said electrodes iii-A and IS-A.

This said rotating medium 3! 'can be made of flint or jena glass or anyone of the many Well known plane rotating mediums such as transparent metallic film and is normally positioned so as to include the said focal point 2i] approximately centrally.

Now let it be assumed for the purpose of this description that-the said plane rotating medium 3| is made of a transparent :dielectric medium 'so as to include end surfaces with elementary por- -tions collectively constituting opposite surfaces of a lens. In other words-the end surfaces ofthe medium 3l vin the path fof the `polarized light l1 are curved 'in this particular embodiment to properly transmit the polarized light'fI-l through the said medium 3 lv.

In this event the planelrotated polarized light 2i VWill be transmitted through the Wave-length affecting double refracting film discs 22--A of the means of Figure 7 (see Figure 10). These discs are .individually seen by Yreferences to Fig.` `and identified by 'the numerals'-22---A,'-.22-C,y 22--D and EEE-F. t is understood that the discs may be replaced by `any-of the wave-changing or retarding-media' hereinafter described and maybe of any desired shape. For example, three of the media of 'wave-aifecting vmeans lof Figure 6 are arranged in three sectors of 120 degreesle'ach 'to completea 360 degrees disc-and the vmedia R may be formed from entirely -v'different--material than the mediatof sectors B and/ or G.

The plane rotated Wave-affected ypolarized-light `24l is fnovv analyzed for color by 'transmission through the analyzing'means 25 `or the'analyzing means of Fig. 5 and Figure -8 as .hereinafter described.

After being plane and/or color analyzed fthe wave affected colored light 242is intercepted 'and reflected from the reflecting surface of the reflectormember 2&5 as colored light 2l-28 converging at a focal point 29 moving as a spot of light according to the characteristics of theparent electron beam Il andthe said vsynchronizing pulses imposed on the leads I8 and i9. 1A conventional'fluorescent screen of the properfcontour is positioned approximately iri the pathof the said moving focal point 29.

lWhile the' reiiecting surface 2S-A to-26-B ofthe reflector member 26 .is-indicatedon the drawingsV as being approximately iiat, .it will be obvious to rthose skilled in the optical art' that the said reflecting surface 25-B vmay also be, curved -sovas toc'onform to the conditions under Whichthe means of Figure 1 will be installed and operated. In this event, 'the light 21---28-may diverge or converge to the screen 38. The surface of'thev'said screen 3B obviously will be optically related to theconto'ur of the'said reflector surfaceZG-B.

of my invention as shown by Figure 2, there ts indicated a conventional source of an image modulated electron beam 35 generally indicated by the numeral 34 and including the conventional supply terminal leads such as -A and a conventional beam deilecting Winding 55. The said electron beam 35 impinging on the fluorescent screen 36 or other intercepting means provides a source of energy hereinafter designated as light (visible or invisible). This electron beam derived light 31is optically changed into the converging light J by the conventional optical means 38 and dathereafter to be intercepted by the reflecting lsurface of thereflecting member l2 and reflected as light 43 converging to the focal point l2. A Alight polarizing means of more or less conventional design Aas ill Iis operatively positioned in the path of the said converging light 123 between the ree'ctor '-means 42 and the focal point 12.

A plane polarizationirotating means including the plane rotating'medium Slis .preferably positioned symmetricallyr vabout the '.said. focal point 'l2 so as to vapproximately centrally include the same. Conventional electrodes for energizing the medium-2% are kconnected to the supply leads 45 and "H1-,in turn yconnected to asource of .image frame-synchronizing pulses upon which is conventionally superimposed :color :eld` synchronizing pulses.

:The reflected. light 43 plane' 4polarized 4by 1 the polarizing means 441to. :becomeyplane polarized light 'H and plane rotatednbythe means Vfiithence passesthrough the wave-airecti-ng medium 419` as plane rotated light 128 to becomegplane rotated wave-affected polarized light 5B. The saidgcolored light 5i? is analyzed by the'conventional.. analyzer 54 Lto becomecolored -converging `light52 inter- `cepted by the. fluorescent; screen means v53.

By .means of `VFigure 3V there is shown still another modication of the meansofignre 1 corn- ;prising az'source :of either .heterochrornatic or Vdivergin'g light `63 :is wave' affected` and/or retarded kbythe light double refractingwave affectingzmedi-umw .esce Figures 6 and 7). The wave affected light ris then visibly coloredby transmission `through the. analyzing means 66!(see-Fig .uros-'8 and A9) The conventional lensesi'sv and el) of-Figure'- 2 can be placed in-theipathvof thecoloredlight :61 to cause the said light to converge as light fGL-A. (see communes). Without tiefsaid lenses the said lightf'i'' vvillv diverge 1to1-the intercepting interceptingf'means 68 can ibe .adjustably 'moved relativeto the Afocal :point lil- A asv indicatedby `the doublehead'ed- .arrovvzlof 'Figure By means-*of `Figure 9there is shown an additional modiiication `.of thev means-of Figure l ywhereby a1beam'oflight 7M Lis provided-from a source (nots'hown) and .preferably with parallel rays VA'The lightl Meis .plane polarized by Ameans fof the.: adjustable 'rotatableU toothed polarizing means yI5 1(see '.Fig. ll) tootlrconnected to the pin- VReferringhowto "another of thermodicatonsiu ion 16 mounted on thefrotatablefshaft lll. lA

ably mounted on the shaft 88 so as to selectively and rotatably intercept the wave affected polarized light 85. The colored polarized light 8B is then intercepted by the screen 98. Thus all or" the means of Figure 9 are rotatable. The means 86, 15, 82, 13, 8i! and 90 are preferably adjustably g rotatable about a common axis relative to each other and to the said light.

Let it be further understood for the purpose o this description that the following adaptions to conventional television apparatus combinations are contemplated according to the present disclosure.

` (a) Black and white television receiving means whereby an oscillating electron beam is employed to produce an oscillating beam of light of approximately ccnstantintensity. The said light beam is plane polarized, plane polarization rotated to be modulated by reiiection as a function of the said rotation and intercepted by a screen to visibly appear as a spot of light moving with the characteristics of the said electron beam and Varying in intensity as a function of the said plane rotation.

(b) Non-mechanical color television apparatus whereby an electron beam of approximately constant intensity is produced and light (visible and/or invisible) is derived therefrom to be sequentially and progressively plane polarized, plane polarization rotated, wave-length (frequency) affected and analyzed and thence transmitted to a screen.

(c). Electro-electronic-optical color television apparatus including stationary means whereby an electron beam oscillating with approximately constant intensity is provided and light related thereto is refracted preferably to converge on a reflecting member so as to converge to a focal point and thence diverge to impinge on a light sensitive element or intercepting member such Aas a screen. The said light being plane polarized, plane rotated, and wave-affected and analyzed in accordance with the said oscillation and the said rotation.

(d). Color television appartus whereby an oscillating electron beam is provided with image modulations and the modulated light obtained therefrom is Wave retarded or transformed according to the plane rotation thereof. The polarized colored light is again reflected so as to appear as light moving with the characteristics of the said electron beam and colored in accordance with the said plane rotation.

'(e). Color television apparatus wherein an oscillatingv modulated electron beam is provided and light is obtained from the said beam and optically aifected to pass through a focal point and thence be intercepted by a light sensitive circuit element or a screen.

(f). Coloring apparatus for light whereby polarized light is provided and transmitted through a focal point, plane rotated in the vicinity of the saidfocal point, diverging to be wave retarded or transformed as a function of the said plane rotation. The said light being colored by analyzation and intercepted by conventional means such as screen, light sensitive circuit element.

(g). Television apparatus by means of which the polarized light obtained by the apparatus described by paragraph (f) is optically controlled to converge to a focal point so that the area of the resultant colored light will vary with the relative movement of the intercepting means.

(h) Light decomposing and reassembling means whereby a beam or" light with preferably parallel rays is provided to be selectively plane polarized, plane rotated, wave aifected, analyzed and intercepted by adjustable rotatable. means positioned along the optical axis of the said light.

In, operation Referring to the embodiment of my invention as shown by the means of Figure l, there will be seen conventional apparatus for deriving energy indicated by the numerals I2 and I3 (hereinafter referred to as light) from an oscillating electron beam II. The reected light I5 derived therefrom will have the characteristics of the said beam II as it passes through the correcting lens III-A and thence through the plane polarizing means I to become plane polarized light Il converging to the focal point 26. Let it be assumed that predetermined E. M. F. related to the said characteristics is impressed on the leads I8 and I9 connected to the electrodes IB-A and IS-A to energize the plane polarization rotating medium Si thereby to plane rotate the polarized light Il as it is transmitted through the said transparent plane rotating medium 3l. lf the said E. M. E. impressed on the leads i8 and I9 is related to certain characteristics of the electron beam I i, the rotation of the plane polarization of the plane rotated light will also be related to the said certain characteristics of the said electron beam Il. It is obvious that the medium 3i may also be energized by current related to the said beam I I. In other words, magnetic plane rotated light means will be substituted for the electrically plane rotated light means. The light Il can also be desirably tinted or colored without departing from the spirit of my invention.

The plane rotated light 2| is now transmitted through double refracting wave affecting means 2?. (see Figures 6 and 7) In one embodiment of my invention, the means of Figure 7 consisted of 5 thin sheets Aof cellophane used in wrapping lamp shades. These cellophane sheets were placed between two clear glass discs which were cemented together. I used many different media during the development of my invention, including sheets of mica, transparent Bakelite, sheets selected from the plastic group made of acrylate, cellulose acetate, phenol-formaldehyde, polyvinyl, ethyl cellulose, cellulose nitrate, polystyrene and many other materials.

For the purpose of this description, let it be assumed that several thin sheets of cellophane are used. When the rplane rotated light 2l is passed through the said sheets one after the other as light 24 and thence through the analyzer means '25 (see Figures 8 and 9) the light 2li-A will be uniformly colored. The color will change as the plane polarization is rotated. The light 2li-A will be changed through a sequence of spectrum colors as a function of the extent and direction of said plane rotation. The colors of light 24-A will also change as the said sheets 22-A, 22-C, ZZ-D and 'Z2- F are rotated rela tive to each other without magnetic and/or electricv plane rotation, and will also be colored as both the plane plarizationyard the sheets' are ro:v

' tated. Thevcolors'wilichange as the analyzer is rotated with or without plane and sheet rotation and the analyzed colors' will also change Yas a? function of theV combined relative rotation of the plane,l sheet and analyzer rotation.k

The` dotted lines of Figuren indicate that the'T normal plane polarization liesY in a plane' per-d pendicular to the planev of the paper upon which Figures is drawn. In .theI same manner ythe dotted lines of Figure indicate that the normal plane of analyzation lies' in the same plane as the plane polarization' of light l1. Thusn'or-i m'ally` the normally plane polarized light Il' will be passed by the analyzer 25 when not wave affected by the double refracting means 22. Or the analyzer 25 may be rotated to extinguish the light, L i.

"With theV proper numberof doublerefracting sheets (see Figure of the selected media in positionV as shown by Figure 1 and'A with theorialyzer set at the proper angle for thecond'itions` under which ,theV device will be installedy and operated, thev light 2li-A will be colored'i'n a sequence periodically repeated asa function of the Velectror'i beam related plane polarization r'o`- tation due to the asynchronous and synchronize ing pulses of E.' M. F1 and/or current impressed ontneieads le and I s. If the plastic discs` 22j- Al` 22-c, 'z2-D and 22"-F are" novv' replaced by sector portions" of dises as'R, B and G of y Figilre'l so that the nurnoof of materialjof uio R portions the' imoA of the'. iight are different from the' B and G poft'ions, and the BAportions"are differentH than the G portions, the portions ofthelight ZTIl `passing through theseR, 'andG portions will/be diier'- ently colored forV a given plane polarization rtation'of the light f1. l i

.I"found" that the actual color ofthe light 2HE-A? (when the wave affecting means of Figure 'i is in operating positioni varied)y with angle rotation of' the plane. polarization ot light 2li. With a proper pulse impressedontheleads I3 and li-l,` three distinct? colors as blue, green and yellow were impar-ted to the light 2li- A.

If this impressed-E. M F.- (or current in the case of magneticrotation)` is'related. to the said electron beam il, then the light 2li- A may be colored blue for everythirdsweep of the said'- leam, and thence. green and yellow (or any other desired color) in desired sweep sequence as is required for sequential scanningy Vin color television reception.

VAs the speed of the Kerr cell has been estimated as high as; i118, thenthe color of thev light 2k3-A; may be changedqat the samev speed', or even faster since the three colors may be olo-` tainedduring one; pulse or plane rotation;

I would pointvoutat this time, that many co'mbinations ofv plane polarization, plane polarizae tion rotation',.p olarized light'wave retarding and aiected means and analyzers may be employed by those skilled inthe electroelectronemagneticeoptics art withoutA departing: froml the vspirit of myY inventionr For" example; additionalr optical means may loe-added; to the means of'i Figure 1' at several points, along the optical; axis ofthe" light l5 so that the light Il may pass through the plane polarization rotation mediuml` with'- parallelr'ays and-concentrated'to reduce-the areai Vof the said mediumlal s`o`V as tofin` tur'nreduce the plane rotatingi energy required; .Stilli further; thef analyzing. meansfof Fisure may be'empioyed' so? 8 that the` light- 24-A will be partly extinguishedwithy every degrees of'plane rotation and-'thusa great mixture of colors will be produced-n such amanner that one set of colors willincrease in intensity as the other setis decreased. Y 1

In any eventy the colored light-24-A will be intercepted by the surface ofthe renee-tor-memeA ber 26- so as to be reflected according to thecom tour of the said surface. While thereflecti-ng surface '2S-A- (and Zit-4B) is-indicated `on ythe drawing by a' straight line in order Vto simplify vthe drawing, it is'obvious that the actualformof the' said reflecting surface will be determinedgby the' conditions under which the means of Figure 1'l willbe installed and operated. Letitbe assumed that the rsaid surface is formed so that colored light 2li-A will be reflected as colored light 21-28 to the focal point 29. lA fluorescent screen 30 is positioned to include the pathof the said focal point 2-9. When the memberjiei'sL properly positioned a colored spot of light 29 will move along a zigzag path periodicallyree peated with the characteristics of the said electron beam,. varying in intensity with the saidbeam and colored in accordance with the characteristics ofthe beamv related M. F. (or current) impressed on the electrodes y|8---A and' l9-+-A. y

Accordingto my invention, the colored light 2 9 canl` be given a predetermined color during` the entire scanning period of the activel frameareaor the light may be given a color only duringthe interval of a single sweep by properly relating-v the E. M. F. pulses impressed on the leads-by any onel of manyfknown methods; Thus-the light 2'1-28- may be (say) red for one sweep, blue forthen'ext sweep and greenfor the third sweep' and V thence red againV for the fourth sweep and soonl periodical-ly repeated down (-or across) Athesaidl scanning area.

In this event one scanning line after thev other will be differently colored and the ent-ire area of the frame will not be given the salme color. The plane rotating energy impressedl onthe terminals I8- and I9 of the plane rotating medi-um r 3i will ofcourse be related as hereinheforey statedto the (say) movement characteristics of the said electron beam i I- as hereinbefore described sothat the light coloring action will be definitely related to the movement of the said electron beam.,

It, is of course contemplated` that the means of Figure 1- Will also -be installed and operatedlv under conditions wherein the high speed atiwhi'ch the said light 2T-28- may be Aelectronically colcred, it will be possible to differently color each individual elementary area of the-screen, or sensitive circuitelement 3 0 and thusthe light-2l=-28i will be changed in color manytimes duringa single sweep across the said frame. 'l hisis' true,- hecause the plane rotationofthe saidlight l! can; be Varied as much as 100,000,000 times per second and the color ofthe light can loechanged many times duringv a single lplaner rotation fn fact, it cariccver the spectrum colors twice during a single' piano rotatingoyoie'; Furthermore there are ric'rmoving parts" included in the In'eansf Figurelandthusno inertia to' l'iinit'the speed' of operation; Light flux, elec'triciliix andma'gne'tic' flux will not limit eachother to the*extenttoZ affect the operation' of my-` device.

The meansfof Figure 1 canbe modified so' as to be employed as a black anfd` white receiving Station. Thisi's' true, because' the-said3` deriyed' constantimtensity" piane roi-atedA Iigh'tf-zl' cante permitted io impnigieuireouyi cwiiznfto meats-fi and removed) on the reflecting surface 25-A of the member 25. When the surface of the member 25 is positioned at the proper angle and the plane polarization of the light 24-A is not rotated as it is transmitted through the said medium 3| it will be reected at right angles to the reflecting surface intercepting it at member 26 as incident light. When the plane polarization of the light 2li-A is rotated, it will be reilected as a function of said rotation from the said surface. In accordance with the accepted law in connection with reflected polarized light, the intensity of the spot of light 22 will vary according to the degree of plane rotation of the light 24i-A- The said spot of light 29 will then be moved across the intercepting surface of the member according to the immodulated characteristics of the electron beam il as it is mod ulated in accordance with the renection varying in intensity according to the degree of said plane rotation. Thus the transmitted image will be visibly reproduced on the screen 3S in the saine manner as taught in my U. S. llnatent No. 2,225,922

vissued December 24, 194.0.

The operation of the modification of my invention as shown by Figure 2 is somewhat similar to the operation of the means of Figure l when used as a color mixer control for scanning, a color receiver television or for black and white receiving. The light 3T! derived from the electron beam 35 is passed through conventional lenses 38 and di? so as to be converged as light 4l to the reflecting surface of the member i2 to be conventionally retracted through a focal point 'l2 to the screen 5:3. The light @i3 is plane polarized by the light polarizing means l-i and plane rotated by the rotating medium et. In fact, this reiiected light @33 can be polarized, plane rotated, Wave affected and analyzed by the means of Figures Ll, 5, 6 and 'l in the same manner as hereinbeifore described for the light iii of Figure l except that such action occurs after reiiection from the surface of the member d2. The light i3 can also be plane polarized by reflection from the surface of the reilector Ll?. when the same is provided with a polarized light reflecting surface li2-A-2--B- The said surface forming a portion of such material as black glass or Bakelite.

The means of Figure 3 can be used with or without the electron beam producing means of Figures l and 2. Let it be assumed that the light El is converging and is transmitted through a plane polarizing nie-ans 58 and a plane rotating means 52 symetrically positioned about the focal point 57i-A. The light 63 will be plane rotated according to the characteristics of the energy impressed on the leads l and 6l. The light E3 is then transmitted through the Wave affecting means El! constructed similar to the means and l or the like. The wave aiected light is then analyzed by the analyzer E56. The colored analyzed light is intercepted by the optical means (i3 constituting a screen or a light sensitive circuit element. The said light can also be refracted by transmission through the conventional optical means 32 and 4B of Figure 2 so as to be converged toward the said adjustably intercepting means 53. In this event, the means 58, 62, Sli and t5 may be moved to a required position between the lens member fill and the screene.

According to the modification of my invention as shown by the means of Figure 9 there is provided a beam of light 14 with preferably parallel rays polarized by a rotatable light rpolarizing means l5 in toothed drive relation with the pinion T5 vmounted for rotation with the shaft T! so that the normal plane polarization may be selectively rotated by rotating the shaft Tl. In the same manner the Wave affecting means S2 may be selectively rotated by drive relation with the shaft 84 as hereinbefore described. Thus the plane rotating, plane polarizing, wave affecting actions on the light 'lil may be selectively varied so as to insure a desired interception by the screen means 9S. If the said shafts ll, 34 and 33 are selectively actuated by conventional remotely controlled means (not shown) a great many combinations of plane polarizing, plane polarization rotation, Wave retarding or affecting and analyzation may be selectively produced by the adjustment and rotation of the said shafts.

It will be obvious to those skilled in the electromagneto-electron-optical arts that many Well known and conventional elements can be added to the means shown in the drawings to aifect the light, current and E. M. F. Without departing from the spirit of my invention.

Therefore, While I have shown and described and have pointed out in the annexed claims, certain novel features of my invention, it will be understood that various omissions, substitutions and changes in the form and details of the devices illustrated or in their operation may be made by those skilled in the art Without departing from the spirit of my invention.

Having thus described my invention, I claim:

l. Stationary color television apparatus for changing the color of a beam of oscillating light in a periodically repeated sequence of different colors, which comprises means for plane polarizing the said light, means for rotating the said polarization thereof, doubly refracting means so positioned in the path of the said rotated light as to change the Wave-length of the said light transmitted therethrough according to the said rotation, means for color analyzing the said doubly refracted light according to the Wave-length thereof and screen means for intercepting the said analyzed light, said rotating means being connected to a source of E. M. F. pulses periodically repeated in the said sequence.

2. Color television apparatus for electronically changing the color of an oscillating beam of light in accordance with a sequence of periodically repeated groups of said oscillations which comprises lmeans for producing oscillating plane polarized light, means for rotating the plane polarization thereof according to the said sequence, doubly refracting media selected from the group consisting of acrylate, cellulose acetate, phenol-formaldehyde, polyvinyl acetate, ethyl cellulose, cellulose nitrate, cellulose acetate-butyrate and polystyrene positioned in the path of the said plane rotated light so as to change the Wave-length of the portions of the said light transmitted therethrough according to the said sequence, means for color analyzing the said transmitted light according to the Wave-length thereof and Screen means for intercepting the said color analyzed light, said rotating means being connected to a source of E. M. F. pulses repeated in the said sequence.

3. Simultaneous all-electronic color television apparatus for reproducing a colored image Which comprises cathode ray tube means energized for producing an oscillating electron beam having the characteristics of the said image, optical means for obtaining a beam of light from the said tube having the characteristics of the said electron beam, means for plane polarizing the said light,

means connected to a source or image synchronizing pulses for rotating the plane polarization, doubly refracting means so positionedin the path of the said rotated light .as to change the wavelength of the said light transmitted therethrough according to the said rotation, means for color analyzing the saiddoubly-reracted light according to the said change and screen meanspositioned for intercepting the said analyzed light as to cause same to visibly appear as light changing color according to the said rotation :and varying in motion and .intensity with the said electron beam, said image synchronizing .pulses being modulated by superimposed color eld synchronizing pulses related to the said energization of the said tube.

4. Color television receiver apparatus which comprises cathode-ray tube means energized so as to provide an oscillating electron beam moving along a periodically repeated zig-zag screen path,

optical means for obtaining a beam of light from the said tube screen having the characteristics of the said electron beam and to direct the said obtained light lwith reduced oscillations through a plane normal to the optical axis of the said light, means'for plane polarizing the said obtained light, means for rotating the planeof the said polarized light at and near the said normal plane, means constituting portions of doublyrefracting material rotatable in planes norm-al to the said optical axis and positioned yone after the other in the path of the said rotated light as to change the Wave-lengthv of portions of the said light transmitted therethrough accordingv to the said plane rotation-and the said por-.tion rotation, means for color analyzing the said transmitted light according to the change in wave-length thereof and screen means positioned for intercepting the said color analyzed light .so as to'cause same to visually appear as a .spot of light chan-ging color according to the said rotations and having the characteristics of the said l.electron beair..

5. Color television apparatus comprising cathode-ray tube means providing an :oscillating modulated beam of electrons whenenergized, optical means arranged for obtaining alight beam from said tube means having the characteristics of the said electron beam, means for plane polarizing the said'obtained light, magneto-optical'means for rotating-the said plane polarization in certain frame and iield relation to the said characteristics, means comprising portions of doubly-refracting material symmetrically :positioned about the optical axis of the said beam and in such phase relation as to respectively doubly-refract portions of the said beam transmitted therethrough in a'different band of Wave-lengths,^

means for analyzing the .said transmitted light according to the band Wave-length thereof and screen 'means for intercepting the said analyzed light, said rotating means connected to a source of frame and field synchronizing E. M. F. pulses related to the said energization of the saidtube.

6. All-stationary television receiver apparatus for electronically -changing the wave-lengthrof a beamv 'of oscillating light during a given oscillation which comprises cathode lray tube means for providing the said light with an initial oscill`atr ving length, a :first optical` meansfordirectingthe said light 'with reduced oscillatinglength through a' 'plane normal to thev optical vaxis of the said light, means for -plane polarizing Vthe said light,

means "for rotating-the said polarization at and adjacent to the said plana/said rotating means being connected to a source of E.M. F. pulses related to the said oscillation, doubly-refracting means for changing the wave-length of the 'said rotated lightaccording to the said pulses,a 'co1or analyzing member for analyzing the said refracted light and a second optical means for directing the said analyzed light to a screen member..` l

7. Simultaneous color television receiver apparatusior reproducing a colored image which comprises an image reproducing cathode ray tube comprising a source of image modulated oscillating light, optical elements for directing the said light through two spaced apart focal planes respectively normal to the optical axis of the said light, means for plane polarizing the said directed light, means for rotating the plane polarization of the said polarized light, means for doublyrefracting the said rotated light, means for color analyzing the said retracted light according to the said rotation and screen means positioned approximately at one of the said focal planes, said rotating means being positioned approximately at the other said focal plane and connect.- ed to a source of E. M. F. pulses related to the color characteristics of the said image and the said oscillations.

8. All-electronic stationary color television apparatus for producing a sequence of 4differently coloredl portions of a ray of light during a single oscillation of the said ray, which comprises means for polarizing the said light, means for rotating the said polarization, a first doubly-refracting means, a second doubly-refracting means, color analyzing means and screen means,

said means being positioned Vone after the other TID along the optical axis of the said light, said doubly-reiiacting means constituting sheet-like portions of materialcapable of doubly refracting the said light into at least two bands of Wave-lengths, said rotating member being-connected to a source of E. M, F. pulses varying according to the said sequence during the said oscillation.

9. YAn all-electronic simultaneous color television receiver system which comprises cathode ray tube means for providing a beam of image modulated light oscillating over a rst area Ylying in a first plane normal to the optical-axis of the said beam, optical means for directing the said light through a smaller second area lying in a second plane normal to the said optical axis, means positioned between the said planes for polarizing the said light, means for rotating the plane polarization of the said light, doubly-rerracting means for changing the Wave-length of the rotated light directed therethrough according to the said rotation, means for color analyzing the said doublyrefracted light according to the said rotation and screen means for intercepting the said analyzed light, said rotating means being connected to a source of E. M. F. pulses related to the said oscillations and the color characteristics of the said image, said doubly-reiracting means comprisingmaterial for doubly-reiracting plane polarized light varying over at least two bands of Wave-lengths.

10. Color television receiver apparatus'for yco1- voring a beam ofY image action modulated light, cathode ray tube means for providing the said light when energized, optical means for directing the said light in a converging manner, means for reflecting the said converging light through a focal plane normal to the optical axis of the said reflected light, means for plane polarizing `the said reected light, means for rotating the said plane polarization at and adjacent the said plane, means for doubly-refracting the said plane rotated light transmitted therethrough, means for color analyzing the said refracted light and screen means for intercepting the said analyzed light, said rotating means connected to a source of image frame synchronizing pulses upon which is superimposed color eld sychronizing pulses related to the said image actions.

11. Electronic color A television apparatus for coloring picture modulated light according to the color characteristics of the said picture,

which comprises cathode ray tube means providing the said light when energized, means for polarizing the said light, means for plane rotating the said polarized light, means for doubly-refracting the said rotated light, means for color analyzing the said refracted light, means for reilecting the said analyzed light and screen means for intercepting the said reected light, said plane rotating means being connected to a source of picture synchronizing pulses, said pulses being related to both the said characteristics and the said modulations, said doubly-refracting means 14 comprising at least two adjustable elements positioned one after the other along the path of the said light.

HOWARD J. MURRAY.

REFERENCES CITED The following references are of record in the lc of this patent:

UNITED STATES PATENTS Number Name Date 1,913,795 Deisch June 13, 1933 2,109,540 Leishman Mar. 1, 1938 2,118,160 Cawley May 24, 1938 2,163,530 Thieme June 20, 1939 2,184,999 Land Dec. 26, 1939 2,225,922 Murray Dec. 24, 1940 2,263,684 Ryan Nov. 25, 1941 2,301,254 Carnahan Nov. 10, 1942 2,328,219 Land Aug. 31, 1943 2,350,892 Hewson June 6, 1944 2,393,968 Burchell et al. Feb. 5, 1946 

